The Twenty-Five Year Lick Planet Search

Fischer, Debra A.; Marcy, Geoffrey W.; Spronck, Jo W.

doi:10.1088/0067-0049/210/1/5

Cited by 129 publications

(133 citation statements)

References 48 publications

(58 reference statements)

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“…These CCFs are removed from our final analysis in Section 3.3, and are further detailed in Section 3.4. Fischer et al (2014). The following additional offsets, determined from a circular orbit fit to each data set using EXOFAST, can be applied to place all of the RV measurements onto the same zero-point: g = -21.70…”

Section: Cross-correlation Analysis and Resultsmentioning

confidence: 99%

“…We consider our repository to consist of six separate data sets: HARPS, HIRES, ELODIE, plus three Lick data sets (Lick13, Lick8, and Lick6). The numbers in the Lick data set names denote the dewar associated with each upgrade to the Hamilton spectrograph, which introduced different velocity offsets (see Fischer et al 2014 for further information). Our first step was to model the data sets independently to determine if they supported an eccentric orbit.…”

Section: A Refined Orbital Solution For 51 Peg Bmentioning

confidence: 99%

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Discovery of Water at High Spectral Resolution in the Atmosphere of 51 Peg b

Birkby¹,

Kok²,

Brogi³

et al. 2017

183

244

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We report the detection of water absorption features in the day side spectrum of the first-known hot Jupiter, 51 Peg b, confirming the star-planet system to be a double-lined spectroscopic binary. We use high-resolution ( » R 100,000), m 3.2 m spectra taken with CRIRES/VLT to trace the radial-velocity shift of the water features in the planet's day side atmosphere during 4 hr of its 4.23 day orbit after superior conjunction. We detect the signature of molecular absorption by water at a significance of J , placing it at the transition boundary between Jovian and Neptunian worlds. We determine upper and lower limits on the orbital inclination of the system of  < <  i 70 8 2.2. We also provide an updated orbital solution for 51 Peg b, using an extensive set of 639 stellar radial velocities measured between 1994 and 2013, finding no significant evidence of an eccentric orbit. We find no evidence of significant absorption or emission from other major carbon-bearing molecules of the planet, including methane and carbon dioxide. The atmosphere is non-inverted in the temperature-pressure region probed by these observations. The deepest absorption lines reach an observed relative contrast of´-0.9 10 3 with respect to the host star continuum flux at an angular separation of 3 milliarcseconds. This work is consistent with a previous tentative report of K-band molecular absorption for 51 Peg b by Brogi et al.

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Section: Cross-correlation Analysis and Resultsmentioning

confidence: 99%

Section: A Refined Orbital Solution For 51 Peg Bmentioning

confidence: 99%

Discovery of Water at High Spectral Resolution in the Atmosphere of 51 Peg b

Birkby¹,

Kok²,

Brogi³

et al. 2017

183

244

View full text Add to dashboard Cite

show abstract

“…), or from spectroscopy. Radial velocity (RV) data from Fischer et al 2014), direct inspection of the FEROS spectra, and the check for possible dependencies of the results of the abundance analysis on wavelength of the spectral lines seems to exclude this scenario. Only very special orbit configurations (wide orbits with extremely small projected separation at the time of the imaging observations) are not yet ruled out by available observations, however their occurrence probability is vanishingly small because of tight observational constraints.…”

Section: Age Summarymentioning

confidence: 99%

“…The presence of a massive companion close enough to tidally spin up the central star is ruled out by the RV monitoring performed at Lick Observatory (Fischer et al 2014). The RV time series include 58 measurements over 21.65 years.…”

Section: Ruling Out Stellar Companions and Their Remnantsmentioning

confidence: 99%

A critical reassessment of the fundamental properties of GJ 504: chemical composition and age

D’Orazi

Desidera

Gratton

et al. 2017

A&A

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Context. The recent development of brand new observational techniques and theoretical models have greatly advanced the exoplanet research field. Despite significant achievements, which have allowed the detection of thousands extrasolar systems, a comprehensive understanding of planetary formation and evolution mechanisms is still desired. One relevant limitation is given by the accuracy in the measurements of planet-host star ages. The star GJ 504 has been found to host a substellar companion whose nature is strongly debated. There has been a recent difference of opinion in the literature owing to the uncertainty on the age of the system: a young age of ∼ 160 Myr would imply a giant planet as a companion, but a recent revision pointing to a solar age (∼ 4 Gyr) instead suggests a brown dwarf. Aims. With the aim of shedding light on this debated topic, we have carried out a high-resolution spectroscopic study of GJ 504 to derive stellar parameters, metallicity, and abundances of both light and heavy elements, providing a full chemical characterisation. The main objective is to infer clues on the evolutionary stage (hence the age) of this system. Methods. We performed a strictly differential (line-by-line) analysis of GJ 504 with respect to two reference stars, that is the planethost dwarf ι Hor and the subgiant HIP 84827. The former is crucial in this context because its stellar parameters (hence the evolutionary stage) is well constrained from asteroseismic observations. Regardless of the zero point offsets, our differential approach allows us to put tight constraints on the age of GJ 504 with respect to ι Hor, thereby minimising the internal uncertainties. Results. We found that the surface gravity of GJ 504 is 0.2 ± 0.07 dex lower than that of the main-sequence star ι Hor, suggesting a past turn-off evolution for our target. The isochrone comparison provides us with an age range between 1.8 and 3.5 Gyr, with a most probable age of ≈ 2.5 Gyr. Thus, our findings support an old age for the system; further evidence comes from the barium abundance, which is compatible with a solar pattern and not enhanced as observed in young stars. Conclusions. We envisaged a possible engulfment scenario to reconcile all the age indicators (spectroscopy, isochrones, rotation, and activity); this engulfment could have occurred very recently and could be responsible for the enhanced levels of rotation and chromospheric activity, as previously suggested. We tested this hypothesis, exploiting a tidal evolution code and finding that the engulfment of a hot Jupiter, with mass not larger than ≈ 3 M j and initially located at ≈ 0.03 AU, seems to be a very likely scenario.

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“…This was initially led by the radial velocity observations (e.g., Mayor & Queloz 1995;Marcy & Butler 1996;Udry & Santos 2007;Mayor et al 2011;Fischer et al 2014) and has subsequently been accelerated by the transit detections through Kepler mission (e.g., Borucki et al 2011;Batalha et al 2013;Burke et al 2014). Super-Earths that have 1 − 20M ⊕ 2 by a working definition are very peculiar in the sense that there is no such analogue in the solar system.…”

Section: Introductionmentioning

confidence: 99%

Super-Earths as Failed Cores in Orbital Migration Traps

Hasegawa

2016

ApJ

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We explore whether close-in super-Earths were formed as rocky bodies that failed to grow fast enough to become the cores of gas giants before the natal protostellar disk dispersed. We model the failed cores' inward orbital migration in the low-mass or type I regime, to stopping points at distances where the tidal interaction with the protostellar disk applies zero net torque. The three kinds of migration traps considered are those due to the dead zone's outer edge, the ice line, and the transition from accretion to starlight as the disk's main heat source. As the disk disperses, the traps move toward final positions near or just outside 1 au. Planets at this location exceeding about 3 M ⊕ open a gap, decouple from their host trap, and migrate inward in the high-mass or type II regime to reach the vicinity of the star. We synthesize the population of planets formed in this scenario, finding that some fraction of the observed super-Earths can be failed cores. Most super-Earths formed this way have more than 4 M ⊕ , so their orbits when the disk disperses are governed by type II migration. These planets have solid cores surrounded by gaseous envelopes. Their subsequent photoevaporative mass loss is most effective for masses originally below about 6 M ⊕ . The failed core scenario suggests a division of the observed super-Earth mass-radius diagram into five zones according to the inferred formation history.

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The Twenty-Five Year Lick Planet Search

Cited by 129 publications

References 48 publications

Discovery of Water at High Spectral Resolution in the Atmosphere of 51 Peg b

Discovery of Water at High Spectral Resolution in the Atmosphere of 51 Peg b

A critical reassessment of the fundamental properties of GJ 504: chemical composition and age

Super-Earths as Failed Cores in Orbital Migration Traps

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